unmap describes itself to agents

A tool or an agent can now find, understand and call the API without a person reading the docs first. Every surface below is served from the site, the API host, or both, and documented under /docs/agents/a2a.

• OpenAPI 3.1 at api.unmap.dev/openapi.json, an RFC 9727 catalog at /.well-known/api-catalog on both hosts, and /auth.md saying how a key is obtained (by a human; there is no self-registration)
• An MCP server at api.unmap.dev/mcp: Streamable HTTP, five read-only tools (geocode search, reverse and nearby, route, isochrone), authenticated, rate limited and metered like any other client
• An A2A Agent Card at /.well-known/agent-card.json with a real POST /a2a endpoint behind it; a skill call is metered once, as the REST call it stands for